Following sharks into the deep

Cape Cod may
have spotted several sharks this
summer, but when Chris Fischer
and his crew went looking for the
great whites here this month,
there were none.
For days, crew members scanned
the sea from their converted
crabbing vessel, the Ocearch, anchored
in the waters three miles
off the Cape. Then, nine days later,
a giant shark that would become
known as Genie reared her her fin,
and burst into oceanographic history.
Hooked in the corner of her
mouth, she became what Fischer
said was the first great white—all
2,292 pounds of her—to be captured
live off Cape Cod, the home
waters of Jaws.
The Ocearch crew held her for
15 minutes in a cradle off the side
of the boat. A team of scientists attached
a GPS tag to her dorsal fin
and took blood and tissue samples
before releasing her back into the
deep. Now the researchers, and
anyone with an Internet connection,
can follow her movements in
real time online on the “shark
tracker” on ocearch.org.
Catching sharks is something
that Fischer, the founding chairman
of Ocearch, a nonprofit organisation
that facilitates research
on oceans and fish, and his crew
have done scores of times. The
purpose of their mission, said Fischer,
44, is to crack the code of
these fascinating animals. He and
the scientists travelling with him
hope to understand their migratory
patterns and breeding habits.
For some environmentalists,
the mission is not so benign, or
even necessary. They see the live
capture of sharks as more invasive
than other methods of tagging.
Fischer chafes at the criticism;
that one reason for inviting the
media was to open the process to
the public. For example, he said,
tags implanted on sharks through
harpooning are less reliable than
those attached to the fin because
they can fall off after six months.
By contrast, he said, when sharks
are captured, the GPS tags can be
attached securely with a drill.
Dr. Greg Skomal, a shark expert
working for the state of Massachusetts,
was on the Cape Cod
expedition. He has tagged sharks
through harpooning, but this was
the first time he had his hands on a
live one. “Any time you capture a
fish by any methodology, you’re
going to expose it to some level of
stress. But we try to minimise
that”, he said.
But through an instrument
called an accelerometer he could
follow their behaviour after they
were released and see if they were
lying on the ocean bottom, how
fast they were swimming and the
beats of their tails. This was the
first time accelerometers have
been attached to sharks.
Genie is now pinging her location
to satellites and creating a
Hansel-and-Gretel-like online trail
of where she has traveled since
she was tagged.